The report, which has been backed by Australia's top climate scientists and science bodies, says that in some cases Australia's climate has shifted permanently.

Mr Combet says the report underpins the reason why the Government has put a price on carbon.

"These are things that people in the community need to be aware of and of course they are the underpinning reason why the Government has moved to reduce greenhouse gas emissions as part of an international effort to tackle climate change," he told The World Today.

"The scientific facts are very clear and we've got to deal with this issue. You cannot bury your head in the sand like Tony Abbott would have us do."

Mr Combet says Australia is not the only country working to cut emissions.

"From 2015 China will have a national emissions trading scheme, and so will Korea," he said.

"California started carbon pricing from January 1 this year. New Zealand's had an emissions trading scheme for several years before us.

Professor Lesley Hughes, one of Australia's climate commissioners, says the report should highlight the urgency of acting to cut greenhouse gas emissions.

"To stabilise the climate to within a level that we can all live with, we really need to start acting sooner rather than later. So that's why we call this the critical decade," she told The World Today.

"Over the last few decades, because we have put more greenhouse gases into the atmosphere, there is a lot more energy in the climate system.

"And because warmer air is capable of holding more water, there's a lot more capacity for extreme events like heavy rainfall.

"The best analogy is to imagine that the climate system is like rolling a dice.

"And we have now loaded the dice so that certain outcomes are becoming more probable.

"And those outcomes are the sorts of extreme events, many of which we have seen over this last summer."